This invention relates to a bag shaped container forming apparatus, in a packing machine for packing contents into a container in the shape of a rectangular hexahedron which is formed by folding sheet materials, and more particularly to a double bag forming apparatus for packing cigarettes into a packing container formed of a double bag of an aluminum foil and a package paper.
Hereby, it should be noted that the packing form which the present invention intends is not limited to the cigarette packing and therefore, the apparatus according to the present invention is not limited to the use for packing cigarettes. Likewise, a first packing sheet material and a second packing sheet material which will be described later are not limited to an aluminum foil and a package paper. Instead, it should be understood that other materials can be selected depending on the circumstances. However, in view of the fact that this type of packing forms are mostly used for packing cigarettes and development of improved apparatus thereof is desired, the present invention will be described hereunder in the form of cigarette packing.
The afore-mentioned configuration of the package of cigarettes, i.e., a rectangular hexahedron shape, which is made of sheet materials is well known and called a "soft pack". In an automatic packing machine for making the soft pack package, a bag shaped packing container with its one end opened is formed or prepared beforehand at one position of the packing machine and a group of a predetermined number of cigarettes, for example, a group of cigarettes consisting of 7 pcs., 6 pcs. and 7 pcs. in three layers, are formed at other position thereof, and the latter is inserted into the former. In this way, the packing means for forming a bag shaped packing container with its one end opened beforehand with the help of a packing container forming apparatus and thereafter inserting a group of cigarettes therein is advantageous when applied to the packing of such goods as cigarettes which are very easily damaged, by using soft sheet materials. Therefore, many attempts have been made to develop this type of packing machines in recent years. In this type of machines, the folding and sealing works for said opening end portion is effected in a succeeding step in order to complete a packed goods.
Heretofore, a forming apparatus for a packing container is generally called an arbor turret, wherein arbors formed of a core metal in the shape of a square sleeve are equally spacedly arranged on the circumference of a packing drum constituting a part of packing machine in the rotary disc form, and the arbor turret is intermittently rotated around the rotary shaft of the drum. In the vicinity of the path for the arbors, there are provided a sheet of aluminum foil feeder and a sheet of package paper feeder and a number of container forming mechanisms, such as folding claws, etc. for forming a bag, all of which are designed to undertake such works as feeding of aluminum foil sheet, winding and folding the same around the arbors, folding of the one end portion thereof, or feeding of a sheet of package paper, winding and folding the same, folding of one end portion thereof, sealing, etc. All of these works or functions are effected, while the arbor turret is temporarily stopped in the process of its intermittent rotation. On the other hand, the above-mentioned aluminum foil and package paper feeders, etc. are also assigned with such works or functions as winding and folding the sheet materials with respect to the arbors, while the arbor turret is being rotated. Also, a group of predetermined number of cigarettes prepared at another position or step are inserted through said opening end portion of the bag shaped container by way of said opening of the sleeve of the arbor, and simultaneously, a pusher is activated to push out said bag from the arbor, while the arbor turret is temporarily stopped in the process of its intermittent rotation. In this way, a packing container is formed by the function of said container forming mechanism synchronous to the intermittent rotation of the arbor turret.
In this packing container forming apparatus or in a packing machine including said apparatus, the apparatus or packing machine is required to be rotated intermittently in order to effect a certain kind of works or functions, as mentioned above, which results in limitation of productivity of said machine. Of course, there are many other causes which are considered to be limiting the productivity of this type of packing machine. For example, a transfer speed between one step to another, and a speed acceleration are allowed only in a limited extent, since such goods as cigarettes are readily damaged. However, if it could successfully eliminate or improve said certain kind of works or functions which are required to be effected while the arbor turret is stopped as mentioned above, and a continuous rotation could be achieved instead of an intermittent rotation, productivity of the machine would be significantly increased.
To this end, there is disclosed in Japanese Patent Publication (Kokoku Publication after examination) Nos. 46-26840, 47-40399 and 48-33400 an improved packing machine, wherein a packing drum is caused to be rotated in a consecutive manner, and arbors formed of a square-sleeve-shaped core metal and mounted on a packing drum are wound around with a sheet of aluminum foil and package paper in order to obtain the above-mentioned double bag with one end portion thereof closed. According to this prior art, however, during a full rotation of the packing drum, the aluminum foil sheet is fed to the surface of the arbors, the folding work is effected and in addition, a sheet of package paper is fed thereupon and another folding work is effected in order to obtain a double bag with its one end closed. Furthermore, in the above art, sheet supporting members for feeding said packing sheet materials as well as forming devices thereof are provided in a position outside the arbors. Furthermore, since a number of processes are required in bag forming mechanisms such as the folding of the packing sheet materials for forming a double bag, etc., a long distance is required for said bag forming processes. Because of the foregoing, the packing drum is required to be made large in its diameter, and the drum is obliged to be arranged in such a manner as to be rotated on the horizontal plane.